Recently, a cerebral folate deficiency syndrome has been described. The clinical picture is one of developmental delay/regression, cerebellar ataxia, with or without seizures, with or without autism. This disorder is treatable with folinic acid. If your patient fits the clinical picture we can measure 5-methyltetrahydrofolate in the CSF we already have if you wish to add on this test. Please see: Ramaekers VT, Blau N. Cerebral folate deficiency, Dev Med Child Neurol. 2004 Dec;46(12):843-51. Cerebral folate deficiency has also been described in mitochondrial disorders.

We now have biomarkers for folinic acid/pyridoxine responsive seizures (Antiquitin, ALDH7A1) that appear on our neurotransmitter metabolite chromatogram.